Question

I’ve got a regex that’s matching a given pattern(obviously, thats what regex’s do) and replacing that pattern with an anchor tag and including a captured group. That part is working lovely.

String substituted = content.asString().replaceAll("\\[{2}((?:.)*?)\\]{2}",
                                       "<a href=\"#!p\\:$1\">$1</a>");

What I can’t figure out is how to url encode the captured group before using it in the href attribute.

Example inputs

1. [[a]]
2. [[a b]]
3. [[a&b]]

desired outputs

1. <a href="a">a</a>
2. <a href="a+b">a b</a>
3. <a href="a%26b">a&b</a>

Is there any way to do this? I haven’t found anything that looks useful yet, though once I ask I usually find an answer.

Answer 1

Sure ‘nough, found my answer.
Started with the code from Matcher.appendReplacement

Pure java:

Pattern p = Pattern.compile("\\[{2}((?:.)*?)\\]{2}" );
Matcher m = p.matcher(content.asString());
StringBuffer sb = new StringBuffer();
while (m.find()) {
    String one = m.group(1);
    try {
        m.appendReplacement(sb, "<a href=\"#!p\\:"+URLEncoder.encode(one,"UTF-8")+"\">$1</a>");
    } catch (UnsupportedEncodingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}
m.appendTail(sb);

GWT:

RegExp p = RegExp.compile("\\[{2}((?:.)*?)\\]{2}", "g");
MatchResult m;
StringBuffer sb = new StringBuffer();
int beginIndex = 0;
while ((m = p.exec(content.asString())) != null) {
    String one = m.getGroup(1);
    int endIndex = m.getIndex();

    sb.append(content.asString().substring(beginIndex, endIndex));

    sb.append("<a href=\"#!p:" + URL.encode(one) + "\">" + one + "</a>");

    beginIndex = p.getLastIndex();
}

sb.append(content.asString().substring(beginIndex));